Expansion Of Rock Slope Stability Analysis Of A Number Of Issues

Swelling rocks is a type of soft rocks. It expanse and soften when wetting, but shrink and disintegrate when drying. Because of the special engineering properties of swelling rocks, the slopes occur sliding easily, which impact the engineering cost and the working security badly. The region which is mantled by the swelling rocks is very extensive in China, therefore study of the stability of swelling rocks slopes are very useful.The middle line water transportation from south to north engineering in China is one of the most important programs in the 21th century. The length of its'main ditch are 1427.17 kilometers and more than 340 kilometers of the parts cross the expansive soils or rocks. So, how to analyze the stability of the swelling rocks slopes is a key component to complete the engineering.This paper is supported by the program study of the stability of the swelling rocks slopes using the FEM which is a crosshead of programs study of the field experiment treating skills of the swelling rocks ditching slopes in middle line water transportation from south to north engineering. At the same time it is one part of study of the failure mechanism and processing method of expansive soils slopes which is supported by the 11th five-year plan for science and technology. The paper study of the numerical problems in the analyzing of the stability of the swelling rocks slopes, it includes the contents as following1. Generalize strength and swell-shrink characteristics of swelling rocks at the base of indoor experiments. This paper indicated that the strength parameters of swelling rocks are related with moisture content. The swelling-shrink characteristics are impacted by the initial moisture content and dry density. The swelling experiments of the several load steps indicated that the deformation modulus is related with the stress conditions. When the swelling rocks in the state of compressive the deformation modulus is lager than it is in the swelling conditions.2. Compare the physical characteristics of the swelling rocks in Xinxiang with the expansive soils in Nanyang, there are some visible differences. The dry density, modulus of compression and shearing stress of swelling rocks in Xinxiang is lager than expansive soils in Nanyang, but plasticity index, colloidal particle content, and free expansion rate of the expansive soils in Nanyang is lager. The swelling rocks in Xinxiang have strong disintegrative that is the expansive soils in Nanyang have not.3. Analyze the constitutive models and parameters of the swelling rocks in the numerical simulation analysis in the FEM and deduce the relation between the deformation modulus and stress conditions.4. Study the principles, stability criterion, parameters sensibility and dependence with the mesh of the method of reduction the strength of shear to compute the stability of slopes. Otherwise, compare the result with the rigid limit equalization method.5. Apply the skill of kill elements in ABAQUS to simulate different K0 status in excavation and analyze the influence of different K0 status for the stability of swelling rocks slope.6. Analyze the stability in the excavation course of the slopes which have different slope ratio and width platforms, then apply the method of reduction the strength of shear to study the influence of sloping surfaces features for the stability of swelling rocks slopes. Analyze the stress and strain of the slope after excavation to obtain the failure mechanics of the unloading slopes.7. According to the principle of temperature stress field equivalent the humidity stress field, adopt the temperature module of ABAQUS to simulate the swelling because of the moisture absorption. Analyze the deformation rule and the stress change in the course of the swelling and compare the change of the stability factor of the slope before the moisture absorption and after.8. Study the influence of cracks and suggest a simplified model to simulate the factor of cracks structures.9. Suggest the later working of the study of swelling rocks slopes.